1. Field of the Invention
The present invention relates to a portable container suitable for keeping fish alive while being transported, and which is provided with a vent in the top wall.
2. Description of the Prior Art
Conventionally, portable containers for transporting young fish, shrimp and the like have utilized oxygen sealed above the water surface inside the container or oxygen or air mixed with oxygen which is airfoamed into the water inside the container by an air pump.
However, when keeping a container under a sealed condition for a long period of time the temperature inside the container gradually rises, which is undesirable for feeding fish, shrimp and the like; and further, this causes an increase in the pressure inside the container which cuases the fish, shrimp and the like to die from shock due to impact upon clashing. For this reason, a generally employed solution has involved providing an inlet on the top of the container which is connected to the air pump and an outlet for venting the air injection-foamed into the container as set forth above. Thus, the container is usually in an open state, so that when the container is momentarily inclined or goes up and down due to swing during transportation, the water inside the container tends to leak out from the air vent. This problem is particularly accute when carrying the container by hanging it from the shoulder as a shoulder bag with the user's clothes getting wet; and when carrying the container by car, the motion of the car causes the seats and the like to get wet. Further, since the walls of a conventional fish container are formed with a completely opaque body, the fish and the like accommodated in the container can not be directly watched, thus making the container unsuitable for use as an ornamental container. Moreover, because the top and bottom ends of the container are of single layer construction, there has been a problem in strength, particularly in winter when the wall surfaces formed of synthetic resin are damaged due to their hardened state.